Polymerase Chain Reaction (PCR) has been widely used to amplify a specific region of a DNA or RNA strand across several orders of magnitude, generating thousands to millions of copies of a particular DNA or RNA sequence. It has long been adopted as a standard procedure in the detection of nucleic acid targets due to the technique's sensitivity and accuracy. Droplet microfluidics' ability to rapidly generate isolated reaction chambers serves as a convenient platform for the adaption of PCR. Because of the synergy, droplet PCR or digital PCR has garnered much research interest in recent years. Real-time PCR is a tool for DNA or RNA quantification that measures the accumulation of DNA or RNA product after each round of PCR amplification.
Conventionally, as a polymerase enzyme completes the complementary strand, a fluorescent label is released from a fluorescent probe, creating a fluorescent signal that is detectable optically. However, the need for fluorescent illumination as well as detection and the processing required to prepare fluorescent markers generally increases the cost of such systems.